This invention relates to devices for cutting grooves in concrete. More particularly, this invention relates to a skid plate used on a concrete saw where a rotating cutting blade extends through the skid plate to cut a groove into the surface of the concrete, preferably before the concrete has hardened.
There are advantages to cutting grooves in concrete surfaces soon after the concrete is finished, without waiting until the next day after pouring. If the concrete is cut with an up-cut rotating blade, and if it is cut before it has hardened sufficiently to avoid raveling, then it is advantageous to support the concrete surface adjacent the cutting blade during cutting as described in U.S. Pat. Nos. 4,769,201 and 5,305,729. This support greatly reduces raveling. Raveling is a term that refers to spalling, chipping, cracking or other undesirable deformation of the surface adjacent the grooves cut in concrete surfaces.
But even using saws of the type described in these patents to cut concrete shortly after it is finished, intermittent raveling of the groove edges occasionally occurs. This raveling is especially common on the larger saws that use cutting blades of about 10 inches (25 cm), or more, in diameter. This raveling is usually attributed to some unknown defect in the saw construction or to operator error of some unknown sort.
Because it is desirable to have a groove with a consistent quality of finish, and preferably to have a groove with minimal raveling, there is a need to prevent this occasional, intermittent raveling.